Method of forming rolled seams on preserve tins and the like



Jun. 23,. 1940. H. ZEIGMEISTER 2,188,291

METHOD OF FORMING ROLLED SEAMS 0N PRESERVE TINS AND THE LIKE Filed Nov.50, 1937 it without.-

Patented Jan. 23, 1940 UNITED STATES PATENT OFFICE METHOD OF FQB'MINGROLLED 'SEAMS ON PRESERVE TENS AND THE LIKE- Herbert Zelgmeister,Hamburg-Wandsbek,

Germany 2 Claims.

This invention relates to preserve tins and the like the body of whichis provided with a longitudinal, rolled seam and is also connected tothe.

end pieces by means of rolled seams. I

In, tins of this kind an hermetic, cooking-proof closure between thebody and the end pieces has been obtained by the introduction into eachseam of an elastic packing ring. In order to obtain an hermetic closureof the longitudinal seam, however, it has hitherto been considerednecessary to employ soldering, particularly when the tin has to besubjected to high internal or external pressure.

The object of the present invention is' to obtain an hermetic andcooking-proof closure of such tins without the employment of solder andwithout materially increasing the cost of manufuture, and the inventionconsists essentially in forming a longitudinal body seam by providingthe blank of the body with radial, outwardly directed flanges, arrangingbetween said flanges a strip of elastic packing material, rolling theflanges together to form the seam, and finally compressing anddepressing the seam so that it will be flush with the outer surface orthe tin. I In connecting this body with the end pieces by means ofsimilar seams, the problem presents itself of how to avoid accumulationof material and consequent leakage-at the point where the longitudinalbody seam meets the seams oi the end pieces. This problem is solvedaccording to the invention by reducing the four corners of the bodyblank to a depth substantially equal to the'width of the material usedup in the,

seaming. This reduction is effected by an oblique cut with straight orcurved outline, so that the tearing stress will be propagated along saidoutline without weakening and tearing the metal.

The removal of the corners has the-further advantage that the ends ofthe longitudinal packing strips will be exposed for joint inclusion withthe packing rings in the seams whereby the body is connected to the endpieces. In this manner a perfectly reliable, hermetic and cooking-proofclosure of the tin will be obtained which will resist high pressure fromwithin as well as from different steps of the improved method panyingdrawing.

. Figa land 2 of said drawing illustrate the,"

fir'ediittibn' ofthe corners of the body blank,

. Fig. 3 shows the application of the packing strip to one longitudinaledge of the blank,

are illustrated by way of example in the accom- Fig. 4 is a sectionalview showing the flanges formed at the opposing edges of the blank,

Fig. 5 is a similar view showing the flanges brought together forseaming,

Fig. '6 is a sectional view showing the flanges 5 rolled together toform the seam.

Fig. '7 shows the seam compressed and depressed,

Fig. 8 is a side view of one end of the body after it has been flangedfor connection to the end Piece.

Fig. 9 is a. sectional side view oi' the flanged body taken across thelongitudinal seam,

Fig. 10 is a sectional view showing the end piece placed in seamingposition, and

Fig. 11 is a sectional view showing the completed seam.

In making the tin, the body blank is formed with reduced corners I and 2which are cut with straight or curved outlines 3 and I. To one of theopposing edges of the blank a packing strip 5 of rubber or the like isattached, the strip being long enough to project at both ends over thereduced corners, as shown in Fig. 3. The opposing edg as of the blankare then bent to a sharp angle so as to form flanges 6 and I (Fig. 4),the flange I, which carries the packing strip being somewhat longer thanthe other. The two flanges are brought together as shown in Fig. 5 andthen rolled over together with the packing strip, as shown in Fig. 6, soas to form the seam. In-the process the packing strip will be flattenedand spread out so as to form an hermetically closed joint. Finally theseam is compressed and depressed as shown in Fig. 7 so that it will beflush with the outer surface of the tin.

The ends of the cylindrical body thus formed are then bent 011' inoutward direction, as shown in Figs. 8 and 9, so as to form, in knownmanner, the flanges or lipsfwhereby the body is connected to the endpieces. The dished end pieces 9 are provided with wide. marginal flangesIII to which packing rings 8 are applied, whereupon the end pieces areplaced in position on the flanged body as shown in Fig. 10. Theprojected end of the packing strip 5 is placed between the ring 8 andthe flange of the body. The seam is subsequently formed in a machine byrolling the flanges together with the packing elements between them. Inthis process the ends of the strip .5 will be intimately combined withthe rings 8, so that the joint'wlll be perfectly tight all round thetin.

The invention is not restricted to the manuiacture oi preserve tins. Itmay also be applied to cans for the reception of oils and fat, the top65.

resilient material; forming radial outwardly di-.

rected flanges at the opposing edges of the blank, the flange at theedge to which the packing strip is attached being longer than the otherflange; bringing the flanges together and rolling said flanges and thestrip spirally together'with the longer flange on the outside to form alongitudinal seam; and compressing and depressing said seam so that itis flush with the surface of the container. 2. The method of making asheet metal container having a side flanging seam provided with apacking strip consisting in cutting a blank for the body of thecontainer reducing the four corners of said blank to a depth equal tothe width of material used in seaming; attaching to one of the opposingedges 0! the blank a packing strip of resilient material, said stripextending at the ends beyond the corner cuts; forming radial outwardlydirected flanges at the opposing edges of the blank, the flange at theedge to which the packing strip is attached being longer than theotherflange; bringing the flanges together and rolling said flanges andthe strip spirally together with' the longer flange on the outside toform a longitudinal seam; and compressing and depressing said seam sothat it is flush with the surface of the container; forming flanges onthe ends of the seamed body; placing closing pieces against the flangesof the body; inserting elastic packing rings between the closing piecesand the body flanges; bringing said rings and the ends of the strip intoa mutually overlapping position; and spirally'rolling the flanges, theends of the strips, the margins of the closing pieces, and said packingrings together to form closing seams.

HERBERT ZEIGMEISTER.

